The Address Locator Tool is an online tool built for the Department of Housing and Community Development (DHCD). It uses information that comes from different sources and in different formats. This file documents all those sources and the intermediate steps required to make the data ready to use it as input.
This file is for internal use and is not intended to be distributed with anyone outside the organization.
This section is organized in the following way: each source of information has its own section and has the code used to create the final dataset. This intermediate dataset can be downloaded as a .csv or .pdf. Each section also has an R script that has more information about each data source.
The DHCD Payment Standard is given by the following file. The Commonwealth of Massachusetts is divided into 23 Metropolitan areas and, for each area, there are the payment standards for the different number of rooms. The smaller geographical unit is the boundaries of a city or a town. In contrast, HUD SAFMR sets its Payment Standard based on zip codes. Smaller than cities and towns, but not as small as census tracts. The Address Locator Tool’s geographical unit are, indeed, the census tract. These differences between different geographical units presents a challenge in how to manage the data that will serve an input for the ALT. To update the DHCD Payment Standards file, there are several intermediate steps required to make the information useful.
The original file provided by DHCD is a Word document that defines which city belongs to each one of the 23 Metropolitan areas. To make this information more easy to use, it has been transformed into the following Excel file, called “Cities by DHCD Metro Area” . This file is the starting point for the upcoming analysis, our original file.
DHCD divides its operation in 8 diferent regions. The list that links each city to each region is published in this link. Based on the Original File, we added the DHCD Regions column.
In order to add the zip codes to the file from point 2.1.1, we retrieve information regarding the zip codes from the following website Zipcodestogo.com. That information has been cleaned and merged with the original file. Please note that there are many zip codes (and cities and towns) that do not have a DHCD Metropolitan Area assigned.
## Reading layer `ma_municipalities' from data source `/Users/lauticantar/Google Drive/DHCD-tool/data/shapefiles/ma_municipalities' using driver `ESRI Shapefile'
## Simple feature collection with 351 features and 5 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -73.50821 ymin: 41.23875 xmax: -69.92751 ymax: 42.88678
## epsg (SRID): 4326
## proj4string: +proj=longlat +datum=WGS84 +no_defs
In order to check that we are covering the whole state, we run the following test. We downloaded a shapefile of all the municipalities in Massachusetts from MassGIS and compare the number of cities and towns between our original file and one downloaded. When we do this, we realize that the original file has missing cities and towns. There are 351 municipalities in Massachusetts and our original file has only 318, thus we are missing 33. As we can see in the map below, most of the missing information are cities from Franklin County.